High-tech devices like 'magic jacks' were used by callers of Mira Road call centres, who posed as US tax authorities to dupe a large number of citizens of that country of several million dollars, police said today.

Police are also looking forward to crack DID (direct inward dialling) number of the devices used by racketeers to find out more about their modus operandi.

DID is used as a way to re-use a limited number of physical phone lines to handle calls to different published numbers.

Assistant Commissioner of Police (Crime) Mukund Hatote, who is leading the probe, told a magistrate's court here that the accused in the case are not revealing anything to police even as the prosecution sought extension of police custody of one of the accused Sufiyan Abdulla Marjurki (25).

According to police, money was transferred from Marjurki's bank account to the accounts of his brothers, wife, and mother.

"Police have definite information that Magic Jacks (MJs) were used in the fraud," Hatote told the court, adding that investigators are trying to get hold of MJs which can be concealed anywhere and which has a DID.

Magic Jack is a device that plugs into a USB port on the user's computer and has a standard RJ-11 phone jack into which any standard phone can be plugged. This allows the user to make unlimited phone calls to the US and Canada.

"Once we get the device and crack its DID, we will travel further and find out details like recipients of the calls and also trace other vital details," the police officer said.

He said police were investigating other financial transactions of the arrested accused whose family members are believed to have played a vital role in the probe.

"The probe will take considerable amount of time as the entire racket involved a number of call centres along with hundreds of associate accused," Hatote said.

Police have so far arrested 71 people in the case.

During hearing of the case on October 10, the court had remanded 54 of the accused in judicial remand, four persons in police custody till October 13 and 13 men in police custody till October 14. Police remanded three others, excluding Marjurki, in police custody till October 20.

The racket was exposed after city police raided three call centres, which were run illegally on the premises of Hari Om IT Park, Universal Outsourcing Services and Oswal House in Mira Road locality in Thane district recently.The callers used to seek financial and bank details of

the US citizens and if the victims refused the information, they would allegedly threaten them with dire consequences, including legal action and penalties.

The callers used to contact people in the US and conned them after speaking in American accent by posing as officials of US Internal Revenue Service, police had said.

According to police, some of the call centre employees earned up to Rs one lakh per month as a reward by the racket operators for making US nationals cough up money.

The employees were fully trained in US accent and were given SOP and call sheet, based on which they used to make calls to the 'tax defaulters'.

They used to make at least 100 calls per day of which 10-15 calls would materialise and of these 3-4 people would make payment under threat by the conmen, police said.

As per police, the daily turnover of these call centres is said to be to the tune of nearly Rs one crore to Rs 1.50 crore, while the annual turnover could be well above Rs 300 crore.